There is a continuing interest in efficiently converting from DC to AC power under controlled conditions and from AC at one frequency to AC at another frequency.
The following U.S. patents are examples of the prior art:
The U.S. Pat. No. 3,564,390 apparatus accepts a lower power frequency then samples the lower power frequency at a high sample frequency. By using a high frequency transformer, which is lighter, the weight of the power supply can be lessened. The lower frequency is then reconstructed at the output of the high frequency transformer but at a higher voltage.
U.S. Pat. No. 3,882,369 pertains to a circuit for controlling the cycle of silicon controlled rectifiers.
U.S. Pat. No. 3,321,693 pertains to producing three phase power by chopping DC power using a three phase oscillator as a control signal.
The U.S. Pat. No. 3,249,845 apparatus converts the frequency of error signals so that an error signal at one frequency may be used to control a servo transducer which is only responsive to another frequency.
U.S. Pat. No. 2,776,379 shows a circuit for creating output power at a constant frequency even though the input power frequency varies.
U.S. Pat. No. 3,517,297 pertains to a circuit for intermixing a low and high frequency signal to produce a signal having the frequency of the difference of the frequencies of the high and low frequency signals.
U.S. Pat. No. 3,742,336 pertains to a circuit which converts AC or DC to polyphase AC, single phase AC, or DC output voltage particularly adapted to drive a variable speed AC motor.